DAB389IL-2 is an interleukin-2 receptor-specific tusion toxin produced with recombinant DNA techniques by expression of a fusion gene in E. coli. We are evaluating the safety, tolerability, pharmacokinetics and biological effects of this agent in patients with moderate-to-severe plaque type psoriasis. Psoriasis is an immunologically mediated skin condition characterized by infiltrates containing activated IL-2 receptor (IL-2R) lymphocytes.